受容体の活性化により,ファゴサイトーシス中の内面ポテンシャルが変化します
Tony Yeung1, Mauricio Terebiznik, Liming Yu
1Division of Cell Biology, Hepatology, and Nutrition Department, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada.
Science (New York, N.Y.)
|July 22, 2006
まとめ
研究者は,細胞表面の潜在力を測定するために,遺伝子でコードされた探査機を開発しました. 彼らは,ファゴシトーシス中にマクロファージ膜の有意な電荷変化を観察し,信号分子の相互作用に影響を与えました.
科学分野:
- 細胞生物学 細胞生物学
- 膜バイオフィジックス
- 免疫学 免疫学とは
背景:
- 生物膜の表面電位は,脂質組成によって影響を受けます.
- 膜ポテンシャルのダイナミックな変化を理解することは,細胞プロセスにとって極めて重要です.
- 生きている細胞の膜潜在性を評価するための既存の方法は限られている.
研究 の 目的:
- 完ぺきな細胞における膜表面電位を測定するための遺伝子でコードされた探査機を開発する.
- マクロファージのファゴシトーシス中の血の電荷の変化を調査する.
- 膜ポテンシャルを調節する脂質リモデリングの役割とその信号伝達への影響を解明する.
主な方法:
- 遺伝子でコードされた光探査機の開発.
- マクロファージのファゴシトーシスの生細胞イメージング.
- 膜脂質組成の変化の分析.
- 膜関連シグナル伝達タンパク質の放出を評価する.
主要な成果:
- 遺伝子でコードされた探査機は,マクロファージの内部プラズマ膜表面潜在力の局所的な変化を測定することに成功しました.
- ファゴシトーシス中に,特にファゴソームカップで,膜電荷の有意な変化が観察されました.
- フォスホイノシチドの水解とフォスファティジルセリンの置換は,観察された潜在的な変化の主要な寄与者として特定されました.
- 信号分子 (K-Ras,Rac1,c-Src) の膜ターゲティングを媒介する静電相互作用が破壊され,変化した膜サブドメインから迅速に放出されました.
結論:
- 遺伝子でコードされた探査機は,生細胞のダイナミックな膜潜在的な変化を研究するための強力なツールを提供します.
- ファゴシトーシス中の脂質再構成は,マクロファージのプラズマ膜表面潜在力を動的に変化させます.
- 膜表面電荷の変化は,ファゴサイトーシスに関与する重要なシグナル伝達分子の局所化と機能に大きく影響する.
関連する概念動画
02:15Replicative Cell Senescence
Replicative cell senescence is a property of cells that allows them to divide a finite number of times throughout the organism's lifespan while preventing excessive proliferation. Replicative senescence is associated with the gradual loss of the telomere — short, repetitive DNA sequences found at the end of the chromosomes. Telomeres are bound by a group of proteins to form a protective cap on the ends of chromosomes. Embryonic stem cells express telomerase — an enzyme that adds the telomeric...
01:16Cell Motility through Blebbing
Blebs are a type of membrane protrusion formed by the internal hydrostatic pressure of the cytoplasm. Blebs are observed in several cell types, including fibroblasts, immune cells, and single-celled organisms like the amoeba. The primary function of blebs is cell locomotion and apoptosis, but they are also found during necrosis and cell division. The life cycle of a bleb comprises an initiation phase followed by the expansion and retraction phases.
Blebbing Through the Matrix
In multicellular...
Blebbing Through the Matrix
In multicellular...
01:15Activation of Integrins
Integrins bind ligands and transmit information from outside the cell to inside or vice-versa through an "outside-in signaling" or "inside-out signaling."
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.
01:29Somatic to iPS Cell Reprogramming
Reprogramming alters the gene expression in somatic cells, transforming them into induced pluripotent stem (iPS) cells over several generations. Scientists can reprogram cells by introducing genes for four transcription factors—Oct4, Sox2, Klf4, and c-Myc (OSKM) by viral or non-viral methods. These factors are also known as Yamanaka factors after Shinya Yamanaka, who first generated iPS cells using mouse skin cells. Yamanaka was awarded the Nobel Prize in Physiology or Medicine in 2012 for this...
01:32Chromatin Modification in iPS Cells
Chromatin modification alters gene expression; therefore, scientists can add histone-modifying enzymes, histone variants, and chromatin remodeling complexes to somatic cells to aid reprogramming into pluripotent stem (iPS) cells.
Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...
Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...
01:27Molecular Factors Affecting Cell Division
Several external and internal factors influence the initiation and inhibition of cell division. For instance, the death of nearby cells or the release of human growth hormone (hGH) promotes cell division. In contrast, lack of hGH or crowding of cells can inhibit cell division.
Several proteins function as internal regulators to ensure each cell cycle stage is completed faithfully before proceeding to the next. Regulator molecules may act directly or influence the activity or production of other...
Several proteins function as internal regulators to ensure each cell cycle stage is completed faithfully before proceeding to the next. Regulator molecules may act directly or influence the activity or production of other...